Korean people drink lots of soju (the Korean version of the
Japanese sake). Why? Some-one finally discovered the reason.
A smart marketing trick: 7 glasses in a bottle.
Why is this smart? Well, if you drink with two people, you can
have three glasses each. One glass is left. Because you
cannot drink by yourself, you need to order one more bottle.
If you drink with three people, you can have two glasses
each...
Get the picture? ;-)